EP 0960069 A1 19991201 - IMPROVED METHOD FOR PROCESSING BAUXITE RICH IN ALUMINA MONOHYDRATE
Title (en)
IMPROVED METHOD FOR PROCESSING BAUXITE RICH IN ALUMINA MONOHYDRATE
Title (de)
VERBESSERTES VERFAHREN ZUR BEHANDLUNG VON ALUMINIUMMONOHYDRATREICHEN BAUXITEN
Title (fr)
PROCEDE AMELIORE DE TRAITEMENT DE BAUXITES RICHES EN MONOHYDRATE D'ALUMINE
Publication
Application
Priority
- FR 9800104 W 19980121
- FR 9700850 A 19970122
Abstract (en)
[origin: US2001012498A1] Process for treating alumina monohydrate-based bauxite by high-temperature caustic digestion characterized in the following series of operations: a) digestion of the bauxite at a temperature in excess of 200° C. with a liquor concentrated to more than 160 g Na2O/liter and having a A/C weight ratio between 0.45 and 0.75, for a contact time which is sufficient to extract the aluminate monohydrate and to attain a A/C ratio between 1.10 and 1.20; b) cooling of the slurry and introducing alumina trihydrate in said slurry, at a temperature of less than 200° C., in order to obtain a A/C ratio of the aluminate liquor between 1.20 and 1.30; c) first diluting to a concentration between 160 and 175 g Na2O/liter; d) settling to separate the insoluble residue from a sodium aluminate liquor with an A/C ratio between 1.20 and 1.30; e) filtering the aluminate liquor; f) lowering the aluminate liquor with a complementary dilution before or during crystallization; g) after separation of the alumina trihydrate by filtration, recycling the spent liquor which, after concentration, is reused as digestion liquor with a caustic concentration above or equal to 160 g Na2O/liter.
IPC 1-7
IPC 8 full level
C01F 7/062 (2022.01)
CPC (source: EP US)
C01F 7/062 (2013.01 - EP US)
Citation (search report)
See references of WO 9832696A1
Designated contracting state (EPC)
DE ES FR GB GR IE IT
DOCDB simple family (publication)
US 2001012498 A1 20010809; US 6296818 B2 20011002; AU 5994098 A 19980818; AU 736050 B2 20010726; CA 2278658 A1 19980730; CA 2278658 C 20070102; CN 1098810 C 20030115; CN 1243496 A 20000202; DE 69802904 D1 20020124; DE 69802904 T2 20020829; EP 0960069 A1 19991201; EP 0960069 B1 20011212; ES 2169904 T3 20020716; FR 2758544 A1 19980724; FR 2758544 B1 19990226; HU 226880 B1 20100128; HU P0001730 A2 20001228; HU P0001730 A3 20020228; WO 9832696 A1 19980730
DOCDB simple family (application)
US 30824499 A 19990616; AU 5994098 A 19980121; CA 2278658 A 19980121; CN 98801842 A 19980121; DE 69802904 T 19980121; EP 98903098 A 19980121; ES 98903098 T 19980121; FR 9700850 A 19970122; FR 9800104 W 19980121; HU P0001730 A 19980121